1. Related Application
This application is related to British Application Ser. No. 8903132.3 filed Feb. 11, 1989.
2. Field of the Invention
This invention relates to a sensing assembly for sensing a transmission neutral condition, and, in particular, to a relatively simple and reliable sensing assembly for use in connection with a multiple shift rail or shift rod transmission shift bar housing assembly for sensing a transmission neutral condition.
3. Description of the prior Art
Multiple speed change gear simple transmissions and/or compound multiple speed transmissions having a multiple speed main transmission section including a multiple shift rod (also called shift rails and/or shift bars) shift bar housing assemblies are well known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,283,613; 4,735,109; 4,788,889 and 4,754,665, the disclosures of which are hereby incorporated by reference.
When such transmissions or transmission sections are utilized with auxiliary transmission devices, such as auxiliary transmission sections, multiple speed drive axles, multiple speed transfer cases or the like, and/or when used with automatic and/or semiautomatic drivetrain control devices, it is often important to have an accurate signal indicative of a transmission neutral, or not neutral, condition. Transmission shift bar housing neutral sensing devices comprising a plurality of separate sensing devices or switches for sensing axial displacement of each of a plurality of separate shift rails from the axially nondisplaced neutral positions thereof may be seen by reference to U.S. Pat. Nos. 4,722,237, and 4,445,393, the disclosures of which are hereby incorporated by reference. Transmission shift bar housing neutral sensing devices comprising an axially displaceable rod having a plurality of specially contoured ramps and grooves (after referred to as a "Christmas tree" shaped rod) extending transverse the axes of the shift rails and cooperating with specifically contouring grooves/ramps therein are known in the prior art as may be seen by reference to U.S. Pat. Nos. 4,676,115 and 4,290,515, the disclosures of which are hereby incorporated by reference.
While the prior art devices were effecting to provide signals indicative of a transmission neutral or not neutral condition, they were not totally satisfactory as they tended to be more complicated and expensive than desired.